1/4+1/8+1/16+1/32+1/64+1/128= 用转化方法做.

问题描述:

1/4+1/8+1/16+1/32+1/64+1/128= 用转化方法做.

=1/2*(1/2+1/4+1/8+1/16+1/32+1/64)=1/2*63/64=63/128